Tiny Bubbles Destroy Tumours in Seven Minutes

Following her diagnosis with liver cancer last June, 68-year-old Sheila Riley braced herself for painful and gruelling treatmentsSurgery, chemotherapy, radio-therapy and even ablation — where heat is used to destroy tumours — are some of medicine’s most effective tools against cancer, but the potential side-effects can be hard to bear. In fact, Sheila was spared these thanks to a radical new form of therapy that uses tiny bubbles of gas to destroy tumours within minutes and doesn’t leave a mark on the body. She was one of the first patients in the UK to undergo histotripsy, where focused ultrasound waves are directed from outside the body to destroy tumours by generating thousands of exploding gas bubbles. So rapid is the procedure that her tumour was obliterated painlessly — in under seven minutes.

It was amazing,’ says the grandmother of eight, who had the treatment last August at St James’s University Hospital in Leeds. ‘I didn’t need any medication — not even painkillers afterwards,’ adds Sheila, who lives in Bradford with her partner Frank, 70. ‘I was able to go shopping the next day, and two days after my treatment I was out with friends. It didn’t even leave a mark on my skin.

It is now hoped the procedure can help those with tumours in other parts of the bodyHistotripsy was pioneered by researchers at the University of Michigan in the U.S. and relies on a process called cavitation — creating an empty space inside something solid — to eradicate cancer. First, a beam of ultrasound energy is directed through the skin to the tumour site. As the beam hits the targeted spot, it activates thousands of pockets of gas that occur naturally in tissue throughout the body, even tumours, as a result of the respiratory process. These tiny pockets of gas are usually dormant, but when blasted with the sound waves, they expand, vibrate and explode, forming a high-energy cloud of microbubbles in the tumour. As they rapidly expand and collapse, the bubbles break up surrounding cancerous tissue, liquifying it into a solution that then gets passed out of the body as waste.

Unlike existing treatments such as microwave ablation, where a heat-generating probe is used to ‘cook’ tumour cells, there is no heat that might damage surrounding healthy tissue, making cavitation potentially safer. This capacity for ultrasound to destroy tissue has been known about for years but was not previously adopted as a cancer treatment because it was too difficult to control the bubble clouds and avoid damaging healthy tissue.

However, the process has now been fine-tuned and the energy source can be better directed inside the tumour, avoiding the risk of nearby healthy tissue or organs being affected. An international trial is now under way looking at histotripsy for liver cancer. The chief investigator, Professor Tze Min Wah, a senior consultant interventional radiologist at St James’s University Hospital, believes cavitation could transform cancer treatment. ‘Rather than using heat, radiation or surgery to remove the tumour, the bubble cloud created by histotripsy is so powerful that it ruptures the tumour but doesn’t damage the tissue around it,’ she says.

Source: https://www.dailymail.co.uk/

Brain Surgery Without a Scalpel

The School of Medicine from the University of Virginia (UVA) researchers have developed a noninvasive way to remove faulty brain circuits that could allow doctors to treat debilitating neurological diseases without the need for conventional brain surgery. The UVA team, together with colleagues at Stanford University, indicate that the approach, if successfully translated to the operating room, could revolutionize the treatment of some of the most challenging and complex neurological diseases, including epilepsy, movement disorders and more. The approach uses low-intensity focused ultrasound waves combined with microbubbles to briefly penetrate the brain’s natural defenses and allow the targeted delivery of a neurotoxin. This neurotoxin kills the culprit brain cells while sparing other healthy cells and preserving the surrounding brain architecture.

A new alternative to brain surgery developed at UVA can wipe out out problematic neurons, a type of brain cell, without causing collateral damage.

This novel surgical strategy has the potential to supplant existing neurosurgical procedures used for the treatment of neurological disorders that don’t respond to medication,” said researcher Kevin S. Lee, PhD, of UVA’s Departments of Neuroscience and Neurosurgery and the Center for Brain Immunology and Glia (BIG). “This unique approach eliminates the diseased brain cells, spares adjacent healthy cells and achieves these outcomes without even having to cut into the scalp.”

The new approach is called PING, and it has already demonstrated exciting potential in laboratory studies. For instance, one of the promising applications for PING could be for the surgical treatment of epilepsies that do not respond to medication. Approximately a third of patients with epilepsy do not respond to anti-seizure drugs, and surgery can reduce or eliminate seizures for some of them. Lee and his team, along with their collaborators at Stanford, have shown that PING can reduce or eliminate seizures in two research models of epilepsy. The findings raise the possibility of treating epilepsy in a carefully-targeted and noninvasive manner without the need for traditional brain surgery.

Another important potential advantage of PING is that it could encourage the surgical treatment of appropriate patients with epilepsy who are reluctant to undergo conventional invasive or ablative surgery. In a scientific paper newly published in the Journal of Neurosurgery, Lee and his collaborators detail the ability of PING to focally eliminate neurons in a brain region, while sparing non-target cells in the same area. In contrast, currently available surgical approaches damage all cells in a treated brain region.

A key advantage of the approach is its incredible precision. PING harnesses the power of magnetic-resonance imaging (MRI) to let scientists peer inside the skull so that they can precisely guide sound waves to open the body’s natural blood-brain barrier exactly where needed. This barrier is designed to keep harmful cells and molecules out of the brain, but it also prevents the delivery of potentially beneficial treatments.

The UVA group’s new paper concludes that PING allows the delivery of a highly targeted neurotoxin, cleanly wiping out problematic neurons, a type of brain cell, without causing collateral damage.

Source: https://newsroom.uvahealth.com/

Ultrasound Can Selectively Kill Cancer Cells

A new technique could offer a targeted approach to fighting cancer: low-intensity pulses of ultrasound have been shown to selectively kill cancer cells while leaving normal cells unharmed.

Ultrasound wavessound waves with frequencies higher than humans can hear—have been used as a cancer treatment before, albeit in a broad-brush approach: high-intensity bursts of ultrasound can heat up tissue, killing cancer and normal cells in a target area. Now, scientists and engineers are exploring the use of low-intensity pulsed ultrasound (LIPUS) in an effort to create a more selective treatment.

A study describing the effectiveness of the new approach in cell models was published in Applied Physics Letters. The researchers behind the work caution that it is still preliminary—it still has not been tested in a live animal let alone in a human, and there remain several key challenges to address—but the results so far are promising.

The research began five years ago when Caltech‘s Michael Ortiz, Frank and Ora Lee Marble Professor of Aeronautics and Mechanical Engineering, found himself pondering whether the physical differences between cancer cells and healthy cells—things like size, cell-wall thickness, and size of the organelles within them—might affect how they vibrate when bombarded with sound waves and how the vibrations might trigger cancer cell death.

I have my moments of inspiration,” Ortiz says wryly.

And so Ortiz built a mathematical model to see how cells would react to different frequencies and pulses of sound waves. Together with then-graduate student Stefanie Heyden (PhD ’14), who is now at ETH Zurich, Ortiz published a paper in 2016 in the Journal of the Mechanics and Physics of Solids showing that there was a gap in the so-called resonant growth rates of cancerous and healthy cells. That gap meant that a carefully tuned sound wave could, in theory, cause the cell membranes of cancerous cells to vibrate to the point that they ruptured while leaving healthy cells unharmed. Ortiz dubbed the process “oncotripsy” from the Greek oncos (for tumor) and tripsy (for breaking).

Source: https://www.caltech.edu/